What am I doing wrong in socket.io configuration?

I'm trying to add instant messaging to an existing app. But I'm not sure how should configure socket.io module. I've already tried the following:

process.env.NODE_ENV = process.env.NODE_ENV || 'development';
const config = require('./config/config.js');

var expressConfig = require('./config/express.js').front,
  models = require('./app/models'),
  passConfig = require('./config/passport-front.js');

const app = expressConfig();
const passport = passConfig();

app.set('port', config.frontPort);
const http = require('http').Server(app);
const io = require('socket.io')(http);

io.on('connection', function (socket) {
  console.log('Connected');
});

models.sequelize.sync().then(function () {
  var server = http.listen(app.get('port'), function () {
    console.log('Express server listening on port ' + server.address().port);
  });

});

module.exports = http;

Since connected is not being logged when I open a page I'm assuming something is missing. Where is my mistake?

via belyid